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1.
Article in English | MEDLINE | ID: mdl-37360841

ABSTRACT

Background: Evidence suggests that patients critically ill with COVID-19 have a dysregulated host immune response that contributes to end-organ damage. Extracorporeal membrane oxygenation (ECMO) has been used in this population with varying degrees of success. This study was performed to evaluate the impact of ECMO on the host immunotranscriptomic response in these patients. Methods: Eleven patients critically ill with COVID-19 requiring ECMO underwent an analysis of cytokines and immunotranscriptomic pathways before ECMO (T1), after ECMO for 24 hours (T2), and 2 hours after ECMO decannulation (T3). A Multiplex Human Cytokine panel was used to identify cytokine changes, and immunotranscriptomic changes in peripheral leukocytes were evaluated by PAXgene and NanoString nCounter. Results: Differential gene expression of 11 host immune genes was noted at T2 compared with T1. The most significant genes were MD2 and MRC1, which code for binding ligands for the activation of toll-like receptors 2 and 4. Reactome analyses of differential gene expression demonstrated an impact on many of the body's most important immune inflammatory pathways. Conclusions: These findings suggest a temporal impact of ECMO on the host immunotranscriptomic response in patients critically ill with COVID-19.

2.
Thorac Surg Clin ; 30(4): 395-423, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33012429

ABSTRACT

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm that can only be treated successfully when correctly diagnosed and treated early. The asbestos-exposed population is a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. We review recent work with biomarker development in MPM and literature of the last 20 years on the most promising blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms are covered. SMRP is the only validated blood-based biomarker with diagnostic, monitoring and prognostic value. To strengthen development and testing of MPM biomarkers, cohorts for validation must be established by enlisting worldwide collaborations.


Subject(s)
Biomarkers, Tumor , Mesothelioma, Malignant/blood , Multidrug Resistance-Associated Proteins/blood , Asbestos/adverse effects , Biomarkers, Tumor/analysis , Biomarkers, Tumor/blood , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Calbindin 2/analysis , Calbindin 2/blood , Calbindin 2/genetics , Calbindin 2/metabolism , Extracellular Matrix Proteins/analysis , Extracellular Matrix Proteins/blood , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , HMGB1 Protein/analysis , HMGB1 Protein/blood , HMGB1 Protein/genetics , HMGB1 Protein/metabolism , Humans , Mesothelioma, Malignant/chemistry , Mesothelioma, Malignant/genetics , Mesothelioma, Malignant/metabolism , Multidrug Resistance-Associated Proteins/analysis , Multidrug Resistance-Associated Proteins/genetics , Multidrug Resistance-Associated Proteins/metabolism , Pleural Neoplasms/blood , Pleural Neoplasms/chemistry , Pleural Neoplasms/genetics , Pleural Neoplasms/metabolism , Prognosis , Proteomics
3.
Cancer Epidemiol Biomarkers Prev ; 29(12): 2524-2540, 2020 12.
Article in English | MEDLINE | ID: mdl-32699075

ABSTRACT

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm, which can be treated successfully only if correctly diagnosed and treated in early stages. The asbestos-exposed population serves as a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. This review details the recent work with biomarker development in MPM and the contributions of the NCI Early Detection Research Network Biomarker Developmental Laboratory of NYU Langone Medical Center. The literature of the last 20 years was reviewed to comment on the most promising of the blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms as well as novel studies such as "breath testing" are covered. Soluble mesothelin-related proteins (SMRP) have been characterized extensively and constitute an FDA-approved biomarker in plasma with diagnostic, monitoring, and prognostic value in MPM. Osteopontin is found to be a valuable prognostic biomarker for MPM, while its utility in diagnosis is slightly lower. Other biomarkers, such as calretinin, fibulin 3, and High-Mobility Group Box 1 (HMGB1), remain under study and need international validation trials with large cohorts of cases and controls to demonstrate any utility. The EDRN has played a key role in the development and testing of MPM biomarkers by enlisting collaborations all over the world. A comprehensive understanding of previously investigated biomarkers and their utility in screening and early diagnosis of MPM will provide guidance for further future research.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."


Subject(s)
Biomarkers, Tumor/metabolism , Early Detection of Cancer/methods , Mesothelioma/diagnosis , Female , Humans , Male , Mesothelioma/pathology
5.
Article in English | MEDLINE | ID: mdl-30863365

ABSTRACT

Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer with a poor survival rate. Treatment options are limited at best and drug resistance is common. Thus, there is an urgent need to identify novel therapeutic targets in this disease in order to improve patient outcomes and survival times. MST1R (RON) is a trans-membrane receptor tyrosine kinase (RTK), which is part of the c-MET proto-oncogene family. The only ligand recognized to bind MST1R (RON) is Macrophage Stimulating 1 (MST1), also known as Macrophage Stimulating Protein (MSP) or Hepatocyte Growth Factor-Like Protein (HGFL). In this study, we demonstrate that the MST1-MST1R (RON) signaling axis is active in MPM. Targeting this pathway with a small molecule inhibitor, LCRF-0004, resulted in decreased proliferation with a concomitant increase in apoptosis. Cell cycle progression was also affected. Recombinant MST1 treatment was unable to overcome the effect of LCRF-0004 in terms of either proliferation or apoptosis. Subsequently, the effect of an additional small molecular inhibitor, BMS-777607 (which targets MST1R (RON), MET, Tyro3, and Axl) also resulted in a decreased proliferative capacity of MPM cells. In a cohort of MPM patient samples, high positivity for total MST1R by IHC was an independent predictor of favorable prognosis. Additionally, elevated expression levels of MST1 also correlated with better survival. This study also determined the efficacy of LCRF-0004 and BMS-777607 in xenograft MPM models. Both LCRF-0004 and BMS-777607 demonstrated significant anti-tumor efficacy in vitro, however BMS-777607 was far superior to LCRF-0004. The in vivo and in vitro data generated by this study indicates that a multi-TKI, targeting the MST1R/MET/TAM signaling pathways, may provide a more effective therapeutic strategy for the treatment of MPM as opposed to targeting MST1R alone.

6.
Clin Cancer Res ; 22(12): 3087-96, 2016 06 15.
Article in English | MEDLINE | ID: mdl-26733616

ABSTRACT

PURPOSE: To determine whether serum levels of high mobility group box protein 1 (HMGB1) could differentiate malignant mesothelioma patients, asbestos-exposed individuals, and unexposed controls. EXPERIMENTAL DESIGN: Hyperacetylated and nonacetylated HMGB1 (together referred to as total HMGB1) were blindly measured in blood collected from malignant mesothelioma patients (n = 22), individuals with verified chronic asbestos exposure (n = 20), patients with benign pleural effusions (n = 13) or malignant pleural effusions not due to malignant mesothelioma (n = 25), and healthy controls (n = 20). Blood levels of previously proposed malignant mesothelioma biomarkers fibulin-3, mesothelin, and osteopontin were also measured in nonhealthy individuals. RESULTS: HMGB1 serum levels reliably distinguished malignant mesothelioma patients, asbestos-exposed individuals, and unexposed controls. Total HMGB1 was significantly higher in malignant mesothelioma patients and asbestos-exposed individuals compared with healthy controls. Hyperacetylated HMGB1 was significantly higher in malignant mesothelioma patients compared with asbestos-exposed individuals and healthy controls, and did not vary with tumor stage. At the cut-off value of 2.00 ng/mL, the sensitivity and specificity of serum hyperacetylated HMGB1 in differentiating malignant mesothelioma patients from asbestos-exposed individuals and healthy controls was 100%, outperforming other previously proposed biomarkers. Combining HMGB1 and fibulin-3 provided increased sensitivity and specificity in differentiating malignant mesothelioma patients from patients with cytologically benign or malignant non-mesothelioma pleural effusion. CONCLUSIONS: Our results are significant and clinically relevant as they provide the first biomarker of asbestos exposure and indicate that hyperacetylated HMGB1 is an accurate biomarker to differentiate malignant mesothelioma patients from individuals occupationally exposed to asbestos and unexposed controls. A trial to independently validate these findings will start soon. Clin Cancer Res; 22(12); 3087-96. ©2016 AACR.


Subject(s)
Asbestos/blood , Biomarkers/blood , Environmental Exposure , HMGB1 Protein/blood , Lung Neoplasms/diagnosis , Mesothelioma/diagnosis , Pleural Neoplasms/diagnosis , Acetylation , Adult , Aged , Asbestos/toxicity , Extracellular Matrix Proteins/blood , Female , GPI-Linked Proteins/blood , HMGB1 Protein/metabolism , Humans , Lung Neoplasms/blood , Male , Mesothelin , Mesothelioma/blood , Mesothelioma, Malignant , Middle Aged , Osteopontin/blood , Pleural Effusion/blood , Pleural Effusion/diagnosis , Pleural Neoplasms/blood , Sensitivity and Specificity , Young Adult
7.
PLoS One ; 8(3): e57681, 2013.
Article in English | MEDLINE | ID: mdl-23516416

ABSTRACT

Hyaluronan-linked protein 1 (HAPLN1) which has been shown to be highly expressed in malignant pleural mesotheliomas (MPM), was detected in serum using an electrochemical surface-imprinting method. First, the detection method was optimized using Bovine serum albumin (BSA) as a model protein to mimic the optimal conditions required to imprint the similar molecular weight protein HAPLN1. BSA was imprinted on the gold electrode with hydroxyl terminated alkane thiols, which formed a self-assembled monolayer (SAM) around BSA. The analyte (BSA) was then washed away and its imprint (empty cavity with shape-memory) was used for detection of BSA in a solution, using electrochemical open-circuit potential method, namely potentiometry. Factors considered to optimize the conditions include incubation time, protein concentration, limit of detection and size of electrode. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to confirm selectivity of imprints. With the obtained imprinting control parameters, HAPLN1 was imprinted in duplicate and the detection of spiked HAPLN1 was successfully conducted in serum.


Subject(s)
Biomarkers, Tumor , Biosensing Techniques/methods , Mesothelioma/diagnosis , Mesothelioma/metabolism , Pleural Neoplasms/diagnosis , Pleural Neoplasms/metabolism , Animals , Cattle , Extracellular Matrix Proteins/blood , Extracellular Matrix Proteins/chemistry , Extracellular Matrix Proteins/metabolism , Gold/chemistry , Humans , Myoglobin/chemistry , Potentiometry/methods , Proteoglycans/blood , Proteoglycans/chemistry , Proteoglycans/metabolism , Reproducibility of Results , Serum Albumin, Bovine/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
8.
J Thorac Oncol ; 5(10): 1516-23, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20689445

ABSTRACT

INTRODUCTION: Osteopontin (OPN) is a multifunctional protein with an important but poorly understood role in non-small cell lung cancer (NSCLC) pathogenesis. Moreover, the role of the three known mRNA isoforms (OPNa, OPNb, and OPNc) has not been reported. We hypothesize that OPN isoforms play different roles in determining the metastatic potential of NSCLC. METHODS: We amplified mRNA for each OPN isoform in NSCLC tumors and matched normal lung. The functional impact of each isoform was evaluated by transfecting cDNA plasmids specific to each isoform into NSCLC cell lines and comparing behavior to empty vector controls in scratch closure, cell proliferation, soft-agar colony formation, and Matrigel invasion assays. Gene array was used to evaluate differences in downstream targets and was compared with a panel of markers for epithelial-mesenchymal transition (EMT). RESULTS: OPNa expression was increased in 91% of NSCLC tumors compared with matched lung. OPNa overexpression significantly increased activity in scratch closure, proliferation, soft-agar colony formation, and Matrigel invasion assays compared with controls in all cell lines. OPNb overexpression produced a less significant modulation of function. OPNc overexpression significantly decreased activity in proliferation, colony formation, and invasion assays compared with controls. Expression arrays revealed an increase in EMT with OPNa overexpression but not OPNc. Differences were validated by quantitative reverse transcriptase-polymerase chain reaction. CONCLUSIONS: Overexpression of the individual OPN isoforms in NSCLC results in divergent functional phenotypes. OPNa produced an aggressive phenotype, whereas OPNc produced a more indolent phenotype. Exon 4, which is transcribed in OPNa but absent in OPNc, may be central to this phenomenon and could serve as a target for isoform-specific inhibition of OPN in NSCLC.


Subject(s)
Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/genetics , Osteopontin/genetics , Apoptosis , Biomarkers, Tumor/metabolism , Blotting, Western , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Adhesion , Cell Line, Tumor , Cell Movement , Cell Proliferation , Colony-Forming Units Assay , Epithelial-Mesenchymal Transition , Gene Expression Profiling , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Oligonucleotide Array Sequence Analysis , Osteopontin/metabolism , Protein Isoforms , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Wound Healing
9.
J Biol Chem ; 285(30): 22809-17, 2010 Jul 23.
Article in English | MEDLINE | ID: mdl-20463022

ABSTRACT

The human genome encodes several hundred microRNA (miRNA) genes that produce small (21-23n) single strand regulatory RNA molecules. Although abnormal expression of miRNAs has been linked to cancer progression, the mechanisms of this dysregulation are poorly understood. Malignant mesothelioma (MM) of pleura is an aggressive and highly lethal cancer resistant to conventional therapies. We and others previously linked loss of the 9p21.3 chromosome in MM with short time to tumor recurrence. In this study, we report that MM cell lines derived from patients with more aggressive disease fail to express miR-31, a microRNA recently linked with suppression of breast cancer metastases. We further demonstrate that this loss is due to homozygous deletion of the miR-31-encoding gene that resides in 9p21.3. Functional assessment of miR-31 activity revealed its ability to inhibit proliferation, migration, invasion, and clonogenicity of MM cells. Re-introduction of miR-31 suppressed the cell cycle and inhibited expression of multiple factors involved in cooperative maintenance of DNA replication and cell cycle progression, including pro-survival phosphatase PPP6C, which was previously associated with chemotherapy and radiation therapy resistance, and maintenance of chromosomal stability. PPP6C, whose mRNA is distinguished with three miR-31-binding sites in its 3'-untranslated region, was consistently down-regulated by miR-31 introduction and up-regulated in clinical MM specimens as compared with matched normal tissues. Taken together, our data suggest that tumor-suppressive propensity of miR-31 can be used for development of new therapies against mesothelioma and other cancers that show loss of the 9p21.3 chromosome.


Subject(s)
Gene Deletion , Mesothelioma/genetics , Mesothelioma/pathology , MicroRNAs/genetics , Base Sequence , Cell Cycle/genetics , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p15/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , DNA Repair/genetics , DNA Replication/genetics , Gene Expression Profiling , Genomics , Humans , Mesothelioma/diagnosis , MicroRNAs/metabolism , Neoplasm Invasiveness/genetics , Phosphoprotein Phosphatases/metabolism , Reproducibility of Results , Telomere/genetics
10.
J Clin Oncol ; 28(6): 936-41, 2010 Feb 20.
Article in English | MEDLINE | ID: mdl-20085934

ABSTRACT

PURPOSE Plasma osteopontin (OPN) levels in advanced non-small-cell lung cancer (NSCLC) correlate with therapeutic response and survival, but the utility of plasma OPN for diagnosis and monitoring of early-stage NSCLC has not been investigated. We hypothesize that plasma OPN levels are elevated in early-stage NSCLC and decrease with resection. PATIENTS AND METHODS Presurgery plasma OPN levels (in ng/mL) were measured by enzyme-linked immunosorbent assay (ELISA) in a discovery set of 60 patients with early-stage NSCLC and were compared with data from 56 cancer-free smokers. Presurgery OPN was validated in an independent cohort of 96 patients with resectable NSCLC. The presurgery levels in the latter cohort were compared with matched postsurgery levels. Perioperative OPN levels were correlated with demographics, tumor characteristics, and perioperative events. OPN was monitored during follow-up. Results Discovery set presurgery NSCLC OPN (271 +/- 31 ng/mL) was higher than smokers (40 +/- 2 ng/mL; P = .001). Presurgery OPN was similar in the NSCLC validation cohort (324 ng/mL +/- 20 ng/mL; P = .134). Postsurgery OPN (256 ng/mL +/- 21 ng/mL) measured at mean of 9.8 weeks (range, 2 to 46 weeks) was lower than presurgery OPN (P = .005). Time from surgery significantly impacted postsurgery OPN: OPN < or = 6 weeks postsurgery (303 n/mL +/- 26 ng/mL) was higher than OPN greater than 6 weeks postsurgery (177 ng/mL +/- 29 ng/mL; P = .003). Multivariate analysis noted correlations between albumin and creatinine to presurgery OPN and use of thoracotomy to postsurgery OPN. Recurrence rate was 5% at 29 weeks mean follow-up. OPN at recurrence was elevated from postsurgery nadir. CONCLUSION Plasma OPN levels are elevated in early-stage NSCLC. They are reduced after resection and appear to increase with recurrence. Plasma OPN may have utility as a biomarker in early-stage NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/blood , Carcinoma, Non-Small-Cell Lung/surgery , Lung Neoplasms/blood , Lung Neoplasms/surgery , Osteopontin/blood , Adult , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/pathology , Case-Control Studies , Cohort Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Lung Neoplasms/pathology , Male , Middle Aged , Neoplasm Staging , Prognosis , Retrospective Studies , Survival Rate , Treatment Outcome
11.
J Thorac Cardiovasc Surg ; 139(6): 1587-93, 2010 Jun.
Article in English | MEDLINE | ID: mdl-19818970

ABSTRACT

OBJECTIVE: Osteopontin is a multifunctional phosphoprotein with an important but poorly understood role in non-small cell lung cancer pathogenesis. We hypothesize that osteopontin isoforms (OPNa, OPNb, and OPNc) have divergent roles in non-small-cell lung cancer angiogenesis and divergent impact on vascular endothelial growth factor secretion. METHODS: We examined mRNA expression using reverse transcriptase-polymerase chain reaction primers for 3 osteopontin isoforms in non-small-cell lung cancer and immortalized bronchial epithelial cell lines, and correlated expression with osteopontin secretion into media detected by enzyme-linked immunosorbent assay. Angiogenic properties conferred by osteopontin isoforms were evaluated by transfecting cDNA plasmids specific to each isoform and controls into non-small-cell lung cancer cell lines, H153 and H358 (low endogenous osteopontin) and A549 and H460 (high endogenous osteopontin), analyzing conditioned media on a bovine capillary endothelial platform, and measuring vascular endothelial growth factor levels by enzyme-linked immunosorbent assay. RESULTS: OPNa mRNA expression correlated with osteopontin secretion in cell lines (r = 0.912, P = .0006). OPNa overexpression significantly increased tubule length compared with controls, OPNb had a similar, but less pronounced effect, and OPNc significantly decreased tubule length compared with controls in each cell line. OPNa overexpression was associated with significant increases in vascular endothelial growth factor secretion, whereas OPNb had no effect and OPNc overexpression was associated with significant decreases in vascular endothelial growth factor compared with controls in each cell line. CONCLUSION: We demonstrated divergent effects of osteopontin isoforms on non-small-cell lung cancer angiogenesis and vascular endothelial growth factor secretion. OPNa overexpression was associated with increased bovine capillary endothelial tubule length and vascular endothelial growth factor secretion, whereas OPNc was associated with decreases in both. These findings may lead to therapeutic strategies for selective isoform inhibition in non-small cell lung cancer.


Subject(s)
Carcinoma, Non-Small-Cell Lung/blood supply , Carcinoma, Non-Small-Cell Lung/etiology , Lung Neoplasms/blood supply , Lung Neoplasms/etiology , Osteopontin/physiology , Humans , Neovascularization, Pathologic , Osteopontin/biosynthesis , Protein Isoforms , Tumor Cells, Cultured , Vascular Endothelial Growth Factor A/biosynthesis , Vascular Endothelial Growth Factor A/metabolism
12.
Clin Cancer Res ; 15(8): 2602-11, 2009 Apr 15.
Article in English | MEDLINE | ID: mdl-19351750

ABSTRACT

PURPOSE: Tumor extracellular matrix (ECM) plays a crucial role in cancer progression mediating and transforming host-tumor interactions. Targeting the ECM is becoming an increasingly promising therapeutic approach in cancer treatment. We find that one of the ECM proteins, HAPLN1, is overexpressed in the majority of mesotheliomas. This study was designed to characterize the protumorigenic role of HAPLN1 in mesothelioma. EXPERIMENTAL DESIGN: Overexpression of HAPLN1 was assessed and validated on a large set of normal/mesothelioma specimens on the RNA and protein levels. We also analyzed DNA copy number alterations in the HAPLN1 genomic locus using the array-based comparative genomic hybridization representational oligonucleotide microarray analysis tool. Tumorigenic activities of the HAPLN1 domains were evaluated in vitro on mesothelioma cells transfected with HAPLN1-expressing constructs. RESULTS: We found that HAPLN1 is 23-fold overexpressed in stage I mesothelioma and confirmed it for 76% samples (n = 53) on RNA and 97% (n = 40) on protein levels. The majority of lung cancers showed no differential expression of HAPLN1. Analysis of DNA copy number alterations identified recurrent gain in the 5q14.3 HAPLN1 locus in approximately 27% of tumors. Noteworthy, high expression of HAPLN1 negatively correlated with time to progression (P = 0.05, log-rank test) and overall survival (P = 0.006). Proliferation, motility, invasion, and soft-agar colony formation assays on mesothelioma cells overexpressing full-length HAPLN1 or its functional domains strongly supported the protumorigenic role of HAPLN1 and its SP-IgV domain. CONCLUSION: Overexpression of HAPLN1 and its SP-IgV domain increases tumorigenic properties of mesothelioma. Thus, targeting the SP-IgV domain may be one of the therapeutic approaches in cancer treatment.


Subject(s)
Extracellular Matrix Proteins/metabolism , Lung Neoplasms/metabolism , Mesothelioma/pathology , Pleural Neoplasms/pathology , Proteoglycans/metabolism , Cell Line, Tumor , Cell Movement/physiology , Cell Proliferation , Extracellular Matrix/metabolism , Extracellular Matrix Proteins/genetics , Gene Expression Profiling , Humans , Hyaluronic Acid/metabolism , Kaplan-Meier Estimate , Mesothelioma/genetics , Mesothelioma/metabolism , Oligonucleotide Array Sequence Analysis , Pleural Neoplasms/genetics , Pleural Neoplasms/metabolism , Protein Structure, Tertiary , Proteoglycans/genetics
13.
Biochem Biophys Res Commun ; 382(3): 514-8, 2009 May 08.
Article in English | MEDLINE | ID: mdl-19285954

ABSTRACT

Osteopontin (SPP1) is an inflammatory cytokine that we previously characterized as a diagnostic marker in patients with asbestos-induced malignant mesothelioma (MM). While SPP1 shows both pro- and anti-tumorigenic biological effects, little is known about the molecular basis of these activities. In this study, we demonstrate that while healthy pleura possesses all three differentially spliced SPP1 isoforms (A-C), in clinical MM specimens isoform A is markedly up-regulated and predominant. To provide a clue to possible functions of the SPP1 isoforms we next performed their functional evaluation via transient expression in MM cell lines. As a result, we report that isoforms A-C demonstrate different activities in cell proliferation, wound closure, and invasion assays. These findings suggest different functions for SPP1 isoforms and underline pro-tumorigenic properties of isoforms A and B.


Subject(s)
Cell Transformation, Neoplastic/metabolism , Mesothelioma/metabolism , Osteopontin/physiology , Solitary Fibrous Tumor, Pleural/metabolism , Alternative Splicing , Amino Acid Sequence , Cell Line, Tumor , Cell Transformation, Neoplastic/genetics , Humans , Mesothelioma/pathology , Molecular Sequence Data , Osteopontin/genetics , Pleura/metabolism , Pleura/pathology , Protein Isoforms/genetics , Protein Isoforms/physiology , RNA, Messenger/metabolism , Solitary Fibrous Tumor, Pleural/pathology , Up-Regulation
14.
J Med Chem ; 49(9): 2703-12, 2006 May 04.
Article in English | MEDLINE | ID: mdl-16640330

ABSTRACT

Peroxisome proliferator-activated receptor gamma (PPARgamma) is well-known as the receptor of thiazolidinedione antidiabetic drugs. In this paper, we present a successful example of employing structure-based virtual screening, a method that combines shape-based database search with a docking study and analogue search, to discover a novel family of PPARgamma agonists based upon pyrazol-5-ylbenzenesulfonamide. Two analogues in the family show high affinity for, and specificity to, PPARgamma and act as partial agonists. They also demonstrate glucose-lowering efficacy in vivo. A structural biology study reveals that they both adopt a distinct binding mode and have no H-bonding interactions with PPARgamma. The absence of H-bonding interaction with the protein provides an explanation why both function as partial agonists since most full agonists form conserved H-bonds with the activation function helix (AF-2 helix) which, in turn, enhances the recruitment of coactivators. Moreover, the structural biology and computer docking studies reveal the specificity of the compounds for PPARgamma could be due to the restricted access to the binding pocket of other PPAR subtypes, i.e., PPARalpha and PPARdelta, and steric hindrance upon the ligand binding.


Subject(s)
Drug Design , PPAR gamma/agonists , PPAR gamma/metabolism , Adipocytes/cytology , Adipocytes/drug effects , Animals , Binding Sites , Cell Differentiation/drug effects , Cell Line , Crystallography, X-Ray , Humans , Ligands , Male , Mice , Models, Molecular , PPAR gamma/chemistry , PPAR gamma/genetics , Protein Structure, Tertiary , Transcription, Genetic/genetics
15.
J Med Chem ; 48(26): 8194-208, 2005 Dec 29.
Article in English | MEDLINE | ID: mdl-16366601

ABSTRACT

The synthesis and structure-activity relationship studies of novel indole derivatives as peroxisome proliferator-activated receptor (PPAR) agonists are reported. Indole, a drug-like scaffold, was studied as a core skeleton for the acidic head part of PPAR agonists. The structural features (acidic head, substitution on indole, and linker) were optimized first, by keeping benzisoxazole as the tail part, based on binding and functional activity at PPARgamma protein. The variations in the tail part, by introducing various heteroaromatic ring systems, were then studied. In vitro evaluation led to identification of a novel series of indole compounds with a benzisoxazole tail as potent PPAR agonists with the lead compound 14 (BPR1H036) displaying an excellent pharmacokinetic profile in BALB/c mice and an efficacious glucose lowering activity in KKA(y) mice. Structural biology studies of 14 showed that the indole ring contributes strong hydrophobic interactions with PPARgamma and could be an important moiety for the binding to the protein.


Subject(s)
Indoles/chemical synthesis , Peroxisome Proliferator-Activated Receptors/agonists , 1-Methyl-3-isobutylxanthine/pharmacology , 3T3-L1 Cells , Adipocytes/cytology , Adipocytes/drug effects , Adipocytes/metabolism , Animals , Cell Differentiation/drug effects , Crystallization , Crystallography , Deoxyglucose/metabolism , Dexamethasone/pharmacology , Drug Design , Humans , Indoles/pharmacokinetics , Indoles/pharmacology , Insulin/pharmacology , Isoxazoles/chemical synthesis , Isoxazoles/pharmacokinetics , Isoxazoles/pharmacology , Male , Mice , Mice, Inbred BALB C , Peroxisome Proliferator-Activated Receptors/pharmacology , Structure-Activity Relationship
16.
Protein Expr Purif ; 35(1): 142-6, 2004 May.
Article in English | MEDLINE | ID: mdl-15039077

ABSTRACT

DPP8 is a new member of the prolyl dipeptidases, many of which have important biological functions in vivo. DPP8 catalyzes the cleavage at the carboxyl side of the proline residue at the penultimate position. To study its structure and biochemical properties, we have overexpressed the human DPP8 protein in baculovirus infected Sf9 cells. The protein is soluble and can be purified to homogeneity. Using the chromogenic H-Gly-Pro-pNA as the substrate, a kinetic study shows that purified DPP8 is active and has a similar kcat value as that of DPP-IV, a prolyl dipeptidase that is a drug target for type II diabetes. The kinetic constants of DPP8 are also determined for other chromogenic substrates, and the results indicate that DPP8 has substrate preference at both the P1 and P2 sites. The expression system provides means of better understanding the structure, catalytic mechanism, and biological function of DPP8 protein.


Subject(s)
Dipeptidases/isolation & purification , Dipeptidases/metabolism , Animals , Baculoviridae/genetics , Baculoviridae/metabolism , Cell Line , Dipeptidases/genetics , Humans , Insecta , Peptides/metabolism
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